Some astronomers think that the two gas-giants do not sport solid surfaces secreted beneath their immense and heavy gaseous atmospheres, although others suggest that the jumbo-size duo do, indeed, harbor relatively small cores of rocky-icy stuff. The two other large inhabitants of the outer limits of our Sun's family are Uranus and Neptune, which are both classified as ice-giants, because they harbor large icy cores secreted deep down beneath their heavy, dense gaseous atmospheres which, though very massive, are not nearly as heavy as the gaseous envelopes possessed by Jupiter and Saturn.
An Icy Nest Of Space Eggs. Methone is actually only one member of an icy nest of Space eggs, which also includes the very strange and smooth moons of Saturn, Pallene and Aegaeon. Aegaeon is a very, very small moonlet that also twirls around between Mimas and Enceladus. Like Methone, Aegaeon displays a mysteriously unblemished surface.
Until 2004, no spacecraft had visited Saturn for more than twenty years. Pioneer 11 had snapped the very first up close and personal images of Saturn when it traveled past it in 1979, Voyager 1 flew past Saturn about a year later, and in August 1981, Voyager 2 had its own fleeting but very productive close encounter. At last, on July 1, 2004, NASA's Cassini spacecraft went into orbit around Saturn, and started taking very revealing photographs of this bewitching planet and its many lovely and bizarre moons.